/**
 * lwip DNS resolver header file.

 * Author: Jim Pettinato 
 *   April 2007

 * ported from uIP resolv.c Copyright (c) 2002-2003, Adam Dunkels.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. The name of the author may not be used to endorse or promote
 *    products derived from this software without specific prior
 *    written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS
 * OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
 * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY
 * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE
 * GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
 * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
 * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
 * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

#ifndef __LWIP_DNS_H__
#define __LWIP_DNS_H__

#include "lwip/opt.h"

#if LWIP_DNS			/* don't build if not configured for use in lwipopts.h */

/** DNS timer period */
#define DNS_TMR_INTERVAL          1000

/** DNS field TYPE used for "Resource Records" */
#define DNS_RRTYPE_A              1	/* a host address */
#define DNS_RRTYPE_NS             2	/* an authoritative name server */
#define DNS_RRTYPE_MD             3	/* a mail destination (Obsolete - use MX) */
#define DNS_RRTYPE_MF             4	/* a mail forwarder (Obsolete - use MX) */
#define DNS_RRTYPE_CNAME          5	/* the canonical name for an alias */
#define DNS_RRTYPE_SOA            6	/* marks the start of a zone of authority */
#define DNS_RRTYPE_MB             7	/* a mailbox domain name (EXPERIMENTAL) */
#define DNS_RRTYPE_MG             8	/* a mail group member (EXPERIMENTAL) */
#define DNS_RRTYPE_MR             9	/* a mail rename domain name (EXPERIMENTAL) */
#define DNS_RRTYPE_NULL           10	/* a null RR (EXPERIMENTAL) */
#define DNS_RRTYPE_WKS            11	/* a well known service description */
#define DNS_RRTYPE_PTR            12	/* a domain name pointer */
#define DNS_RRTYPE_HINFO          13	/* host information */
#define DNS_RRTYPE_MINFO          14	/* mailbox or mail list information */
#define DNS_RRTYPE_MX             15	/* mail exchange */
#define DNS_RRTYPE_TXT            16	/* text strings */

/** DNS field CLASS used for "Resource Records" */
#define DNS_RRCLASS_IN            1	/* the Internet */
#define DNS_RRCLASS_CS            2	/* the CSNET class (Obsolete - used only for examples in some obsolete RFCs) */
#define DNS_RRCLASS_CH            3	/* the CHAOS class */
#define DNS_RRCLASS_HS            4	/* Hesiod [Dyer 87] */
#define DNS_RRCLASS_FLUSH         0x800	/* Flush bit */

/** Callback which is invoked when a hostname is found.
 * A function of this type must be implemented by the application using the DNS resolver.
 * @param name pointer to the name that was looked up.
 * @param ipaddr pointer to a struct ip_addr containing the IP address of the hostname,
 *        or NULL if the name could not be found (or on any other error).
 * @param callback_arg a user-specified callback argument passed to dns_gethostbyname
*/
typedef void (*dns_found_callback) (const char *name, struct ip_addr * ipaddr,
				    void *callback_arg);


void dns_init (void);

void dns_tmr (void);

void dns_setserver (u8_t numdns, struct ip_addr *dnsserver);

struct ip_addr dns_getserver (u8_t numdns);

err_t dns_gethostbyname (const char *hostname, struct ip_addr *addr,
			 dns_found_callback found, void *callback_arg);

#endif /* LWIP_DNS */

#endif /* __LWIP_DNS_H__ */
